The pick-up truck, now common in the United States, has had a phenomenal growth over the past dozen years due to its general utility. Although originally a vehicle aimed for use by farmers, contractors and the like for nearly full-time duty as a light truck, the combination of the suburbanization of America with a growth and affluence which supports two or more vehicles to a family has indeed made the pick-up become a common general vehicle. It is now called upon for a wide variety of uses, often chores not intended in the original design of the pick-up truck. One of these chores is the transportation of fairly long lengths of commonly used materials such as lumber, plastic pipe, conduit, etc. which are often more than twice the length of the flat bed portion of the pick-up such that the center of gravity of such material would be outside the rear of the truck, thus resulting in an unstable condition when loaded.
While the manufacturers of pick-up trucks have partially recognized this need by providing trucks of two basic lengths, that is the standard bed and the so-called long bed, even the long bed length is inadequate for truly long loads. The long bed truck also is obviously considerably more expensive than the standard length bed and in many instances the length is not often needed. However, the more expensive long length bedded truck is often purchased in anticipation of the requirements not foreseen at the time of purchase.
Accordingly, it is an object of this invention to provide a substantially simple solution to the occasional carrying of extended loads in a pick-up truck.
It is a further object of this invention to provide a means for carrying extended loads in a short bedded truck.
Another object of the invention is to provide an extension for a standard bed pick-up truck in order to obviate the need for the purchase of a long bedded truck.
Yet another object of the invention is to provide an extension which is removable from the truck and readily stored when not in use but which is simple to mount and utilize when needed.
A further object of the invention is to provide a removable extension for a truck which is supported by means of suspension relative to the bed of the truck.
The need for a temporary bed extension for pick-up trucks and even standard trucks is well recognized. As early as 1921, T. Devencenzi, in U.S. Pat. No. 1,366,771 disclosed an extension frame for a truck which consisted of a plurality of rods and tubes which would telescope and bear a longer load via cantilever support, but with the addition of trailer wheels where necessary. A less awkward solution is set forth by H. Vuori, U.S. Pat. No. 2,468,579 wherein he proposes an extendable platform attached to a pair of rails and a pair of bars extending rearward. Such a system requires redesign of the truck frame members and, thus, was not applicable to existing trucks on one hand and ended up being a cantilevered load on the other hand. M. O. Eggum, U.S. Pat. No. 2,729,499 also proposes a cantilevered rod and tube telescoping design, but the mechanism lay inside the usable truck body volume partially when in use and completely when not in use. Alternately, the telescoping rod and tube device could be stored under the truck body platform, as in the manner of the T. Devencenzi patent with a chain or other "retractable interconnecting member" secured to the truck for "retaining the support frame in its outwardly extended position but not as a major support for the load".
A. S. Cardini, U.S. Pat. No. 2,712,470 proposes a solution similar to that of the Vuori patent except that the telescoping rod and tube are located at the top of the truck carrying frame and the tube becomes an integral unit of the carrying unit frame side walls. The extended load further is supported entirely by cantilever construction. J. M. Tillery, U.S. Pat. No. 4,023,850 discloses a horizontal extension panel structure substantially coextensive with the tailgate in its horizontal position. Brace arms are supplied to help support the cantilevered load, and vertical braces are supplied to rigidize the structure, and transversely located downwardly directed flanges are provided between the tailgate and the edge of the pick-up truck load for securing the rigid structure positionally. The entire rigid panel structure is removable for storage elsewhere.